Outboard motors are often used to power watercraft. These motors have a water propulsion device which is powered by an internal combustion engine. In order to protect the engine from water and other elements, the engine is positioned in an enclosed cowling of the motor.
The size of the cowling is minimized to reduce the air drag associated with the motor. This in turn reduces the space within the cowling in which the engine is positioned. As a result, heat generated by the engine is trapped within the cowling.
The high temperature conditions within the outboard motor cowling reduce the efficiency of the engine, and may result in damage to the engine or its related components. Liquid cooling systems are often employed to reduce the temperature of the engine. Such systems generally include a coolant pump which is driven by the engine and routes coolant through one or more cooling passages through the engine. These cooling systems are designed to cool the engine itself, and are not as effective in reducing the temperature of the air surrounding the engine within the cowling or the associated accessories. As a result, the engine accessories are still often heated to high temperatures and the air which is drawn by the engine for combustion is often at a very high temperature.
In addition, when the engine is stopped, the liquid cooling system stops delivering coolant to the engine. As a result, the retained heat of the engine is transmitted to the engine accessories and the surrounding air within the cowling, raising their temperature very high.
An outboard motor having a water propulsion device powered by an internal combustion engine positioned in a cowling of the motor and arranged to overcome the above-stated problems is desired.